a) \(x-25\%x=0,5\)
\(\dfrac{3}{4}x=0,5\)
x = \(\dfrac{2}{3}\)
b) \(\left(50\%x+5\dfrac{1}{4}\right).\dfrac{-2}{3}=2\dfrac{5}{6}\)
\(\left(0,5x+\dfrac{21}{4}\right)=\dfrac{-17}{4}\)
\(0,5x=\dfrac{-19}{2}\)
x = -19
c) \(\left(1\dfrac{1}{3}-25\%-\dfrac{5}{12}\right)+2x=1,5:\dfrac{3}{5}\)
\(\dfrac{2}{3}+2x=\dfrac{5}{2}\)
\(2x=\dfrac{11}{6}\)
x= \(\dfrac{11}{12}\)
bài 1: tìm x bt:
a\(\dfrac{2}{3}x-\dfrac{1}{2}=\dfrac{1}{10}\)
b, \(5\dfrac{4}{7}:x=13\)
c, (2 và 4/5.x-50) :2/3= 51
d,\(\left(x+\dfrac{1}{2}\right).\left(\dfrac{2}{3}-2x\right)=0\)
e, \(\dfrac{2}{3}-\dfrac{1}{2}x=\dfrac{5}{12}\)
giúp mk nhs!!!!!!!!!!
Bài 1 : Tìm x
a) 4\(\dfrac{1}{2}\)x : \(\dfrac{5}{12}\)=0,5 b)1,5+1\(\dfrac{1}{4}\).x= \(\dfrac{2}{3}\) c) 7,5.1\(\dfrac{3}{4}\)=\(6\dfrac{2}{5}\) d)(x - 5):\(\dfrac{1}{3}\)=\(\dfrac{2}{5}\) e) (4,5-2x):\(\dfrac{3}{4}\)=1\(\dfrac{1}{3}\) f) (2,7x - 1\(\dfrac{1}{2}\)x) : \(\dfrac{2}{7}=\dfrac{-21}{7}\)
Bài 2 : tìm a,b biết
\(\dfrac{a}{27}=\dfrac{-5}{9}=\dfrac{-45}{b}\)
thực hiện phép tính( hợp lí nếu có thể)
\(\dfrac{-5}{9}+1\dfrac{5}{9}.\left(\dfrac{3}{4}-\dfrac{2}{5}\right):7^2\)
\(1\dfrac{13}{15}.0,75-\left(\dfrac{104}{195}+25\%\right).\dfrac{24}{47}-3\dfrac{12}{13}:3\)
\(1\dfrac{13}{15}.\left(0,5\right)^2.3+\left(\dfrac{8}{15}-1\dfrac{19}{60}\right):1\dfrac{23}{24}\)
tìm x
\(60\%x+0,4x+x:3=2\)
\(-2x-\dfrac{-3}{5}:\left(0,5\right)^2=-1\dfrac{1}{4}\)
\(\left(\dfrac{2}{3}-x\right):\dfrac{3}{4}=\dfrac{1}{5}\)
Tìm x biết:
a) \(\dfrac{14}{5}.x-50=34\)
b) \(\left(25\%-2\dfrac{1}{2}\right).2x-\dfrac{5}{4}.2^4=\dfrac{525}{100}\)
1: rút gọn rồi tính
\(\left(-\dfrac{72}{40}-\dfrac{144}{60}-2\dfrac{1}{3}\right)\) : \(\left(\dfrac{45}{100}-\dfrac{25}{60}+-\dfrac{75}{25}\right)\)
2: tìm x: \(3\cdot\left(4-x\right)+\left(x+2\right)\cdot\left(1+2x\right)=7\cdot\left(1+x\right)-2x\cdot\left(2-x\right)\)
3: tìm x: \(\dfrac{2\cdot\left(1+x\right)}{3}-\dfrac{5\cdot\left(2-x\right)}{6}=1\dfrac{1}{3}-\dfrac{3\cdot\left(2x+3\right)}{4}-1\dfrac{1}{2}\cdot\left(x+1\right)\)
4: cho a= \(3+3^{2^3}+3^3+3^4+...+3^{360}\)
Bài 1:
Tìm x biết : x- 0,27 = \(\dfrac{\dfrac{73}{75}+\dfrac{73}{175}\dfrac{73}{285}}{25\left(\dfrac{5}{84}+\dfrac{3}{180}+\dfrac{4}{285}\right)}\)
Bài 2:Tìm 2 số biết \(\dfrac{5}{12}\) số thứ nhất \(\dfrac{3}{16}\)số thứ hai và hiệu của 2 số bằng 52,8
Bài 3:Tìm \(\in\) Z sao cho A=\(\dfrac{n^3-2n^2+3}{n-2}\)có giá trị là số nguyên.
Bài 4:
a) \(\dfrac{-\left(-x\right)}{5}\) - \(\dfrac{2}{10}\) = \(\dfrac{1}{-5}\)-\(\dfrac{7}{50}\)
b) \(\dfrac{x+1}{5}\)= \(\dfrac{7}{x-1}\)
a)x=\(\dfrac{1}{4}+\dfrac{2}{13}\)
b)\(\dfrac{x}{3}=\dfrac{2}{3}+\dfrac{-1}{7}\)
c)\(\dfrac{-8}{3}+\dfrac{-1}{3}\le x\le\dfrac{-2}{7}+\dfrac{-5}{7}\)
d)\(\dfrac{-5}{6}+\dfrac{8}{3}\dfrac{29}{-x}\le x\le\dfrac{-1}{2}+2+\dfrac{5}{2}\)
Bài 1. Tính giá trị biểu thức
125%.\((\dfrac{-1}{2})^2\):\((1\dfrac{5}{16}-1,5)+2008^0\)
\(\dfrac{2}{3.5}+\dfrac{2}{5.3}+\dfrac{2}{7.9}+\dfrac{2}{9.11}+\dfrac{2}{11.13}+\dfrac{2}{13.15}\)
Bài 2. Tìm x, biết
x:\(3\dfrac{1}{15}=1\dfrac{1}{12}\)
\(\dfrac{3}{4}.x=27\)
\(x.\dfrac{1}{4}=\dfrac{5}{8}.\dfrac{2}{3}\)
\(\left(x+\dfrac{1}{4}\right):\dfrac{3}{7}=\dfrac{1}{6}\)
\(\dfrac{3}{4}-2.|2x-\dfrac{2}{3}|=2\)
\(\dfrac{2}{3}x-\dfrac{1}{2}x=\dfrac{5}{2}\)
1. Tim x:
a. \(\dfrac{x}{5}\) = \(\dfrac{5}{6}\) + \(\dfrac{-19}{30}\)
b. \(\dfrac{-5}{6}\) \(-x\) = \(\dfrac{7}{12}\)\(-\) \(\dfrac{1}{3}\)\(\times\) \(x\)
c.2016\(^{^{ }3}\) \(\times\)2016\(^{^{ }x}\) = 2016\(^{^{ }8}\)
d. \((x+\dfrac{3}{4}):\dfrac{5}{2}=3^1_2\)
e. (2,8 \(x\) \(-\) 2\(^5\)) : \(\dfrac{2}{3}=3^2\)
f. \(\dfrac{4}{7}\times x-\dfrac{2}{3}=\dfrac{2}{5}\)
g. \((\dfrac{3x}{7}+1):\left(-4\right)=\dfrac{-1}{28}\)
2. Thuc hien phep tinh:
a. \(\dfrac{1}{2}+\dfrac{1}{2}\times\dfrac{2}{3}-\dfrac{1}{3}:\dfrac{3}{4}+1^4_5\)
b. \(\dfrac{7\times5^2-7^2}{7\times24+21}\)
c. \(\dfrac{2}{3}+\dfrac{1}{3}\times(-\dfrac{4}{9}+\dfrac{5}{6}):\dfrac{7}{12}\)
